The present invention is generally directed to measuring Radon concentration, and more particularly to a method for calibrating an apparatus for measuring Radon and/or its progeny in an air sample.
The deleterious effects of Radon and its progeny on living beings are well known. In this regard, it is recognized that exposure to radiation from Radon and its progeny is the second biggest cause of lung cancer, after smoking. It is also the biggest cause of death from the built environment in which Radon gas can diffuse out of the soil or concrete where they are formed and collect in spaces where people live and work. Various prior art methods and apparatus are available for measuring Radon concentration. One method and apparatus for measuring the concentration of unattached Radon progeny is disclosed in U.S. Pat. No. 6,018,985 (the '985 patent), by the same inventor, which is hereby incorporated herein in its entirety by reference. In the method disclosed in the '985 patent, the concentration of unattached Radon progeny in air is determined by measuring the conductivity of the air or the concentration of fast ions. A multiplying factor is used to convert the conductivity of air to obtain a value representing the concentration of the unattached Radon progeny in the air sample.